Speaking during the summer, Mourinho said he was determined to restore United's status as a heavyweight club in European football following a few lean years in the wake of legendary manager Sir Alex Ferguson's retirement in 2013.

"Manchester United are one of the top three football clubs in the world, no doubt about it, but the football club is one thing and the team's credentials going into a competition are another thing entirely," he was quoted as saying by Manchester Evening News in August.

Jose Mourinho won the EFL Cup and the Europa League with Manchester United last seasonGetty Images

"Our job is to try to bring the football club back to that stature. That's really difficult these days.

"I want the team to be on a par with the club's history, which is something I've been lucky enough to feel at every club.

"We'll improve the team and try to be at that level, to constantly be improving. And I think we're going to reach that level as a football team in the next couple of years."